1. Field of the Invention
The present invention is related to a touch-sensitive apparatus, a control circuit, and a method for scanning a touch event thereon, for the purpose of power saving with great performance, in particular to the apparatus and circuit performing a time-division scanning with different frequencies.
2. Description of Related Art
Many conventional technologies are provided to perform detection of touching position on the touch-sensitive panel. Besides the capacitance-type or resistance-type touch panel generally adapted to the handheld electronic device, a technology using the sensing circuit beneath the panel to detect any sensing signal while a specific electromagnetic conductor approaches the panel. This electromagnetic panel is usually applied to the conventional input device such as digital tablet, digitizer, or electronic white board.
Regarding the conventional technology incorporating a specific electromagnetic object or finger to trigger an electromagnetic event in a touching position, a control and driving circuit is usually provided to control power supplied to the sensing circuit beneath the touch-sensitive panel to perform scanning.
The sensing circuits for the whole panel are used to sense the signals over two directions, such as X and Y axial directions. The sensing circuits of both directions are connected with the driving circuit and control circuit of the panel device. The driving circuit continuously supplies power to the sensing circuits. Every touching point upon the touch-sensitive panel is able to sense signals over the two directions. The control circuit then determines the touching position.
Thus, since the every circuit loop of the sensing circuits of the touch-sensitive panel continuously scans the touching position, it needs long charging time for charging the circuits, and also consumes powers.